Oil burner



J. J. HARMAN Dec. 3, 1935.

OIL BURNER 4 Sheets-Sheet 1 Filed Oct. 12, 1931 INVENI'UR- YMMZWAZJMMKA Dec. 3, 1935. J, J. HARMAN OIL BURNER Filed 001;. 12, 1951 4 Sheets-Sheet 2 o 1 22%|? yh/wllwaifw' 'A ysl 1935- J. J. HARMAN 2,023,072

OIL BURNER Filed Oct. 12, 1951 4 Sheets-Sheet 3 INVEN+EIR;

J. J. HARMAN Dec. 3, 1935.

OIL BURNER 4 Sheets-Sheet 4 Filed Oct. 12, 1951 iii" INVEN+URI Eatented Dec. 3, 1935 OIL BURNER John J. Harman, Newton, Mass., assignor to Walworth Patents Inc., tion of Massachuset Boston, Mass., at corpora- Application October 12, 1931, Serial No. 568,285

' 4 Claims. (01. 15s73) This invention relates to oil burners for domestic heaters and particularly to oil burners of the steam atomizing type.

The usual type of oil burner now in common 5 use in domestic heaters operates on the air atomizing or air vaporizing principle and is a complicated and expensive structure ordinarily requiring a motor, a blower or spinner, fans, pumps, spark plugs, intricate electrical devices and gas pilot lights, and has many moving parts,

all of which greatly increase the expense of manufacturing and operating the oil burner, and which parts are often out of order and require lubrication, cleaning and repair. The electrical equipment also often causes annoying radio interference. These objections, and drawbacks are avoided in large part in an oil burner operating on the steam atomizing principle, but while many attempts to build such burners have been made, they have not been successful for domestic heating.

The chief difliculty has been the proper regulation of the steam supply, such as keeping it at a proper pressure as not to blow out the flame and obtaining a steam of suflicient uniform dryness to properly atomize the oil, and not flood the burner with water to extinguish the flame. Another difliculty has been that previous steam atomizing oil burners have also required exten- 30 sive installation of equipment, and close attention to steam, water, air and oil supplies, and consequently did not provide the simple and compact structure, and automatic regulation of the various operating factors essential in a successful domestic heater.

An object of the present invention therefore is to provide a practical, efiicient and economical burner operating on the steam atomizing principle, suitable for domestic and industrial use and burning a low cost fuel.

A further object is to provide an oil burner of the aforesaid type which consists of a simple compact unit, inexpensive to. make, install and operate, free from intricate mechanical devices, and whose parts would ordinarily need no cleaning or repair, but would be quickly accessible if such were necessary, and thereby to avoid expensive repair and maintenance costs.

A further object of the invention is to provide an oil burner completely automatic in 0peration and which shall require very little or no attention from the owner after once starting it.

An important feature of the invention is its method or principle of operation which consists in maintaining the steam supply substantially constant while varying the oil supply thermostatically in accordance with the heat demands of the house, and automatically varying the amount of air necessary for most efficient com- 5 bustion.

Another important feature of the invention lies in its responsiveness to heat demands through gradual modulation of the flame, and within a short range, as required, rather than through the extreme of having too much flame and completely shutting it off.

A further feature of the invention lies in the provision of an effective water feeding device, whereby the flow of water to the steam genera- 5 tor may be accurately controlled and regulated and whose parts will not deteriorate and require constant replacement, the successful operation of any steam atomizing oil burner in large part depending on the efficiency of the 20 water feeder.

A further feature of the invention lies in the automatic safety trip valve for shutting off the supply of oil should the burner cease to operate at any time and thereby to the burner or cellar with oil.

Other objects of the invention will become apparent from the following description taken in connection with the accompanying drawings, wherein:- 30

Fig. 1 is a side elevation of an oil burner partly in section embodying the invention.

Fig. 2 is a plan View of the same.

Fig. 3 is a front elevation, partly in section, taken on the line of 3-3 of Fig. 1, looking in 35 the direction indicated by the arrows.

Fig. 4 is a section taken on the line of 44 of Fig. 2 looking in the direction indicated by the arrows, and

Fig. 5 is a section taken on the line of 55 of Fig. 1 looking in the direction indicated by the arrows.

Referring more particularly to the drawings,

the oil burner is shown therein as comprising a plurality of units such as the base plate A, the water feeder B, the ignition chamber C, the nozzle housing D, the combustion chamber E, the steam generator F, and the safety trip valve unit G for the fuel line.

- The base plate A is preferably of sheet metal and, in contour, conforms in general to the shape of the units it supports. The base plate may be secured to the floor by means of the leg l0 shown in Fig. 1.

The water feeder B (Figs. 1, 2 and 3) which is prevent flooding of 25 Formed integrally with the feeder body l5 adjacent its upper end is a lateral hollow projec-- tion H carrying a valve body 23. The valve body 23 is provided with a valve seat 25 with whicha valve member 26 cooperates to control the flow of fluid through an aperture 21in the seat. The valve member 26 is provided with a stem 28 hav'-' ing spaced webs 29 thereon engaging the int e rior of the valve body 23 for positioning the valve therein.

Water is conveyed to the valve f-roina suitable source of supply by means of the pipe 26 connected to the valve body 23 by means of the union 2-land nut 24. Preferably a filter plate 22 is interposed between the valve body 23 and the union 2|, as shown in Fig. 3. In order to maintain a desired quantity of water in the feeder the valve stem 28 is connected to a lever arm 32 pivoted on a pin 33 and carrying a float 34- positioned in the body l5-of the feeder.

On the opposite side of the body l5 from the valve is a threaded boss 35 which carries a pipe 62 connected at its opposite end to the steam chamber of steam generator F. In this manner steam is conveyed into the water feeder B for equalizing the pressure between feeder B and generator F.

Mounted on the cover iii of water feeder B is a steam pressure gauge 39 and a pressure relief valve 40. A pipe 46a leads from the relief valve to carry excess steam through the heater door plate 48 and exhaust it into the domestic heater.

The relief valve 40 is preferably of the weighted type so that it may be set to exhaust at certainpressures by merely adding or subtracting aweight such as two and one-half pounds in winter and one and one-half pounds in spring or early fall. The valve will relieve all excess steam whenever the pressure reaches the desired amount. Preferably the valve is designed to operate as accurately 3, possible tomaintain a desired pressure, and eliminate fluctuations on either side of the desired-pressure. Tri-cocks 4! may be mounted on the body I5-at different levels for testing the water levels in the feeder.

A vacuum breaker is provided for the feeder B and comprises a pipe 42-connected to the body l5 at a point below the water level therein. The pipe projects upwardly outside the feeder preferably fifteen feet or more and has its upper end open to the atmosphere. A column of water is carried in this pipe and any vacuum created in the water feeder will draw the water from the p p found in operation of the burner that when the flame goes out and the water'fee der. cools the steam in the feeder condenses creating a suction. The objectionable feature is that the suction draws oil through thesteam nozzle to-clog the water feede'r. Hence, if the vacuum in the feeder is not. permitted to rise high enough-no oil can be drawn through the steam'hozzie.

The ignition chamber c. Figs. 1 and 4, for the burner nozzle comprisesa cylindrical body thus breaking the vacuum. It has been.

45 positioned beyond the water feeder B and secured to the base plate A preferably by welding. One end of the chamber C is closed by a detachable cover plate 41 carrying the steam and fuel nozzle housings D and provided with holes 5 through which the steam and oil supply pipes project. The other end of the housing C is closed by the heater door plate 48 which takes the place of the door of the domestic heater H. An opening 49 is provided in the door plate 48 to allow passage of the flame therethrough from the burner nozzle. The housing C is further provid'ed with a lighting port normally closed by a cover 50.

A starting oil pan 5'! is provided in the bottom of, the housing C for receiving oil dripping from the burner nozzle. The oil pan 5| is partially filled with oil and provided with a braided asbestos wick which may be lighted to provide a starting flame for the burner. An overflow pipe 20 I0 leads from the side of the oil pan- 5| intermediatethe top and bottom thereof to carry off surplus oil to the safety valve unit G to be later described.

Openinginto one. side of the housing C is a 25 draft tunnel cr flue 52 which may be lined with felt 53 to mufllecombustion noise.

A steam nozzle 55 and oil nozzle 56 are secured to the nozzle housing D. The steam nozzle 55 comprises a pipe having an extending 30 lower lip onto which the oil nozzle 56is adapted to drop oil. The steam noz'zleis positioned centrally of opening 49 in door plate 48 to direct the flame through combustion chamber E into the heater H. 35

The combustion chamber E (Fig. l) is a longitudinal passage which confines the burning gases and directs them on to the steam generator F. The combustion chamber as shown is separated from thehousing C by the heater door plate48 40,

therefrom. Surmounting the water leg 50 is a 50 steam chamber 6| into which steam rises. Preferably the steam chamber 6| ispartly exposed to the flame in the combustion chamber to superh'eat the steam therein and thusinsure the dry steam essential for proper combustion. 55

Leading from the upper side of the steam chamber 6i throughthe heater door plate 48 and connected to the water feeder B is a pipe 62. In this manner the steam pressures-in the steam chamber 6| and water feeder B are equalized. 60 Steam is supplied to the steam nozzle 55 by means ofa pipe 63 leading from the pipe 62. Preferably, the pipe 62 is arranged so that it slopes from steam chamber 6| to the water feeder B and the steam pipe 63 before descending to the steam nozzle, thus tending to prevent anycondensate from passing back to the steam chambertl or entering the steam pipe 63;

Fuel, such-as oil; is-supplied to the nozzle 56 70 through pipe 65- as previously described. The supply ofoil-is thermostatically controlled, as shown in Fig. 2, by a valve 66 mounted on the pipe as-ana-comronedby -a lever 61 connected by a chain-68 110 'thethermostatT. The thermois carriedupwardly 65 has failed to operate.

stat may be of any suitable type but is preferably one that regulates gradually through a narrow range without sudden change. A sediment trap (not shown) may be interposed in the pipe 65 to insure the delivery of oil free from impurities to the burner nozzle.

The safety trip valve unit G operates to shut off the fuel supply, if for any reason the burner The outlet pipe 10 is connected to oil pan 5i into which unconsumed oil flows from the oil nozzle and overflows into said outlet pipe 10 which opens downwardly into an oil trip pan H. Preferably outlet pipe is goose-necked to prevent any flames passing therethrough into the oil trip pan H and igniting the oil therein.

The oil trip pan H is mounted on a pan holder 72 which depends from one end of a lever 13. The lever 73 is balanced on a yoke 15 extending upwardly from the base A and has a counterweight 74 on its opposite end. An car 16 is provided at the pan end of the lever 13 and engages a latch H which is tiltable and carries a weight l8. Connected to the latch 11 and rotatable thereby is the stem 79 of a valve 80 which is mounted on the fuel pipe 65 at a point beyond the valve 56. When sufiicient oil overflows into oil drip pan H the lever 73 is unbalanced, latch l! is disengaged and turns valve stem 19 which operates to close valve 80 and shut off the oil supply.

The burner is lowing manner:

The fire is started by lighting the asbestos wick in the oil pan 5| and steam is quickly generated. The steam passes to the steam nozzle 55 adjacent the oil nozzle 55 where it atomizes the oil dropping therefrom and the atomized mixture is ignited by the flame in the oil pan.

The flame is directed through the combustion chamber E by the steam jet and the induced draft to the steam generator F. In passing into the fire box of the domestic furnace the flame heats the air of a hot air system or the Water in a hot water or steam system. The steam generated in the generator F is carried around to the steam'nozzle 55 where it atomizes the oil thereby completing the cycle.

The principle on which the burner operates is that the water delivered to the steam generator is kept at a constant level by the float controlled valve in the water feeder and the steam delivered to the steam atomizer is kept at an unusually low pressure by the relief valve. The amount preferably operated in the folof steam pressure normally maintained depends upon the oil consumption of the burner. In a burner such as that shown in the drawings having an oil consumption range from one-sixth to two gallons per hour the relief valve is set at one or one and one-half pounds at the lower rate of consumption and at two and one-half or three pounds at the higher rate. On larger installations, such as apartment houses or hotels where larger quantities of oil are burned per hour a higher constant pressure up to say five pounds will naturally be required. It is desired to operate on as low a steam pressure as Will atomize the oil properly and keep the burner and heater clean.

The amount of oil delivered to the nozzle and consequently the heat produced is controlled by the thermostat operating the valve in the fuel pipe. The amount of air necessary for efficient combustion is automatically provided at all times by the natural induction effect of the steam jet and flame, which varies with the amount of fuel supplied.

There is thus no fluctuation in the steam pressure which heretofore has ranged from 1 to 15 lbs. and which was continually blowing out the '5 flame at higher pressures when a small amount of fuel was being consumed and which was so difficult to control. With the unusually low oonstant steam pressure disclosed herein this difficulty is eliminated and adequate heat to mainl0 tain a desired house temperature is available at all times.

The fuel supply by this method is not turned on and then completely off as in other methods. The burner is operated continually but the oil 15 off completely. The low steam pressure used does not create the objectionable conbustion What is claimed is, 1 A liquid fuel burne of the class described,

comprising a substantially cylindrical housing chamber therebetween, means for supplying fuel through the housing to said jet to be atomized, a starting fuel pan forming part of the housing wardly of the atomizing device with respect to the 55 for combustion by the inductive action of the atomizing device, a

. relief valve connected to the steam supply means to maintain the steam within a predetermined low pressure range, a control valve for the fuel supply 60 and a thermostat connected to said valve to vary the supply of fuel to vary the heating capacity of the mixture of air, fuel and steam.

3. A liquid fuel burner of the class described, comprising a housing adapted to project partly within a furnace, a steam generator positioned at the end of the housing within the furnace, a fuel atomizing unit in the housing adjacent the opposite end thereof receiving steam from said 70 generator and discharging it in a jet toward the generator, and means for supplying fuel to said steam jet to be atomized, said housing having an inlet for air in one side thereof rearwardly of said atomizing unit, the part of the housing between the steam generator and the atomizing unit conjet to be atomized, said housing having -an inlet stituting a combustion chamber within which for air in one side thereof rearwardly of said substantially complete combustion occurs. atomizing unit, the part of the housing between 4. A liquid fuel burner of the class described, the steam generator and the atomizing unit concomprising a housing adapted to project partly stituting a combustion chamber, and means in 5 within a furnace, a steam generator positioned said housing beneath the atomizing unit for at the end of the housing within the furnace, a igniting the mixture of air, fuel and steam, said fuel atomizing unit in the housing adjacent the mixture undergoing substantially complete comopposite end thereof receiving steam from said bustion in said combustion chamber before reachv generator and discharging it in a jet toward the ing the generator. 10

generator, means for supplying fuel to said steam JOHN J. HARMAN. 

